Keyboard support mechanisms of the type adapted for supporting a keyboard for user induced movement relative to a work station having a front marginal edge arranged to face a user and a downwardly facing mounting surface for mounting such mechanism typically including guide track adapted for attachment to the mounting surface to extend rearwardly of such front marginal edge, a trolley supported by the guide track for movement between a forwardly extended keyboard use position and rearwardly disposed keyboard storage or retracted position; an auxiliary surface or a keyboard support; and a linkage for mounting the auxiliary surface on the trolley for relative vertical movement.
In one of mechanism, a trolley is fitted with plastic guides arranged to be slidably received within facing mounting channels extending lengthwise of marginal edges of a guide track. This construction is suitable for lightweight mechanisms where friction between the guides and mounting channels does not adversely affect sliding movement of the trolley between use and storage positions.
In another type of mechanism adapted for use with relatively heavy mechanisms, wherein excessive frictional forces would be encountered with the use of sliding plastic guides, a trolley is fitted with pairs of rollers arranged to roll lengthwise within the mounting channels. While rolling action tends to substantially reduce a user""s effort required to move the trolley, a drawback of presently known mechanisms is that the auxiliary surface is rendered unstable or sidewise movable when placed in its keyboard use position, due to required clearances between the transverse outwardly facing surfaces of the rollers and the transverse inwardly facing surfaces of the mounting channels necessary to allow for free rolling movement of the trolley without binding engagement with the guide track. An unstable auxiliary surface tends to interfere with normal use of a keyboard and/or mouse supported thereon.
The present invention is directed to an improved keyboard support mechanism, and more particularly, to an improved arrangement for supporting a trolley of such mechanism for movement relative to a guide track by which the mechanism is mounted on a work station or work surface.
In accordance with the present invention, a trolley is fitted with two pairs of rollers arranged to roll lengthwise of a guide track within a pair of edge mounted mounting channels thereof and a follower member; and the guide track is fitted with a guide member having a guide channel adapted to slidably receive the follower member of the trolley. The guide channel extends only part way rearwardly from a front end of the guide track, whereby to cooperate with the follower member of the trolley to stabilize or constrain an auxiliary surface on which a keyboard is supported against undesired transverse or sidewise movement when in its extended keyboard use position, while permitting loose fitting of the trolley within the guide track during a substantial portion of the extent of movement of the auxiliary surface to and from its storage or retracted position.